Qingxia Wang

The promotions of MnO and K2O to Fe/silicalite-2 catalyst for the production of light alkenes from CO2 hydrogenation

Abstract MnO and K 2 O are two kinds of promoters incorporated onto a Fe/silicalite (denoted as Fe/Si-2) catalyst for light olefin formation from CO 2 hydrogenation. Addition of MnO into the Fe/Si-2 catalyst increased the selectivity toward light olefins. Meanwhile, CH 4 yield as well as CO formation were practically unaffected by the MnO addition. Moreover, the conversion of CO 2 was also insensitive to the addition of the MnO promoter. With the addition of K 2 O onto the Fe–Mn/Si-2 catalyst, the selectivity for light olefins increased further, while CH 4 formation was inhibited. An obvious increase in CO 2 conversion was also observed. CO 2 -TPD, CO 2 /H 2 -TPSR and CO/H 2 -TPSR, as well as CO 2 pulse reactions were employed to probe the promotional functions of MnO and K 2 O. The results revealed that CO adsorption capacity was enhanced by the addition of MnO, and that incorporation of K 2 O could further increase both the capacity and bonding strength of the Fe–Mn/Si-2 catalyst with strongly adsorbed CO 2 and CO species. On the basis of a two step reaction mechanism in which a reversible water gas shift reaction and a Fischer–Tropsch reaction are involved, the promotional effects of these two kinds of promoters for the formation of C 2 H 4 and C 3 H 6 can be explained.

Regeneration behaviors of Fe/Si-2 and Fe-Mn/Si-2 catalysts for C2H6 dehydrogenation with CO2 to C2H4

The catalytic performance of Fe/Si‐2 and Fe–Mn/Si‐2 catalysts for conversion of C2H6 with CO2 to C2H4 was examined in a continuous‐flow and fixed‐bed reactor. The results show that the Fe–Mn/Si‐2 catalyst exhibits much better reaction activity and selectivity to C2H4 than those of the Fe/Si‐2 catalyst. Furthermore, the coking–decoking behaviors of these catalysts were studied through TG. The catalytic performances of the catalysts after regeneration for conversion of C2H6 or dilute C2H6 in FCC off‐gas with CO2 to C2H4 were also examined. The results show that both activity and selectivity of the Fe–Mn/Si‐2 catalyst after regeneration reached the same level as those of the fresh catalyst, whereas it is difficult for the Fe/Si‐2 catalyst to refresh its reaction behavior after regeneration.

Research and development of catalytic processes for petroleum and natural gas conversions in the Dalian Institute of Chemical Physics

Abstract The Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences has a long history in the R&D of catalysts and catalytic processes for petroleum and natural gas conversions in China. In this paper, results and features of some commercialized petrochemical catalysts and processes as well as newly developed processes for natural gas conversion in the pilot-plant stage are described.

Study of the Kinetics of the Combustion Reaction on Shuangya Mountain Coal Dust by TG

The combustion behavior of Shuangya Mountain (SYM) coal dust has been investigated by means of TG in this paper. The reaction fraction α can be obtained from isothermal TG data. The regressions of g(α), an integral function of α vs. t for different reaction mechanisms were performed. The mechanism of nucleation and nuclei growth is determined as the controlling step of the coal dust combustion reaction by the correlation coefficient of the regression, and the kinetic equation of the SYM coal dust combustion reaction has been established.

The Carbon Depositing Behavior and its Kinetic Research in Benzene Alkylation Process Over High Silicate ZSM-5 Zeolite

In our invention, FCC (fluid catalytic cracking) dry gas could be used to react with benzene without any special purification, and more than 90% ethylene was converted to ethylbenzene. The phenomenon of carbon deposition over catalyst surface was obvious and leads to a deactivation of catalyst, so it is important to study the behavior of carbon deposition of catalyst during alkylation of benzene. The influence of several factors such as temperature, reaction time, reactant concentration of the amount and the kinetics of carbon deposition were investigated, during which carbon depositing rate equations were obtained for different reactant.

Light olefins from syngas over modified Fischer-Tropsch catalysts

Si-2 zeolite supported Fe-MnO catalyst is shown to be a suitable catalyst for the production of light olefins from syngas. The main roles of MnO promoter are causing better dispersion and reducibility of Fe particles, and the suppression of hydrogenation of the light olefins produced. Tio 2 is a desirable binder which improves the strength of the catalyst and which also causes better catalyst reactivity without any loss in the high selectivity to light olefins.